Smelling gasoline fumes in car's (2001 Ford Focus) interior

For weeks I’ve been smelling gasoline fumes inside the car, ususally when the weather is cold and when the car has been sitting overnight; sometimes while it is idling. Have had to car to my mechanic, who I have confidence in and who has done a good job with repairs in the past. He could not locate the source of the fumes. Anyone esle with a Focus ever had a similiar problem?

The first thing I check when someone complains of a fuel odor is the fuel injector O-rings.

The O-rings can leak while the engine running, and when the engine is turned off from the residual fuel pressure.

It takes very little gas to create that smell.


Also, don’t top off you tank above the gas pumps automatic shutoff. This can saturate the charcoal canister and cause the gas smell. I would go with @Tester on this one. O-rings would be my first suggestion.

What happened to my reply(I answeared this post also) check that little PVC or vent hose on the back of the engine,it’ll let a oil stench in the car(happened to me on a 2000 Focus

The “sitting overnight” part suggests a leak in an evaporative emissions hose. These can be gnawed on by mice looking for nesting places in winter. If the above suggestions don’t help, have the evap system smoke tested smoke tested. The smoke will pinpoint the leak.

Also, if you park your car in a garage that has bags of bird seed or grass seed, put the seed in covered metal trash cans to keep mice away. Free food in winter attracts mice that may nest under the car and chew hoses, etc.

Just curious, is there a safe diy version of a smoke test? Or is that something best done by a pro shop?

Lots of people have made DIY smoke tester videos on YouTube. Here’s a dirt-simple one:

Very clever! Thanks for the utube link. I might be a little worried if I tried this as a diyer’s project to test my car’s evap system a spark from the coals would dislodge and be pushed up through the smoke hose with the arrangement though. I wonder if some kind of spark arrester gadget could be inserted into that path to assure no active sparks make it to the evap system?

Some guy hooked up a cheap Halloween smoke machine and used it on youtube.

I had this problem, and it turned out to be a fuel injector that was leaking